Steel
Steel type: weaknesses, resistances and Pokémon
Steel Pokémon take double damage from Fire, Fighting and Ground moves, resist Normal, Grass, Ice, Flying, Psychic, Bug, Rock, Dragon, Steel and Fairy moves and are immune to Poison moves.
With 11 resistances and immunities against 3 weaknesses, it is a very solid defensive combination.
Steel moves are super effective against Ice, Rock and Fairy and not very effective against Fire, Water, Electric and Steel.
To beat these Pokémon, your best pick is Fire, Fighting and Ground moves. Avoid Normal, Grass, Ice and Flying moves, which deal little or no damage.
There are 10 Pokémon with this combination, such as Registeel, Klink, Klang and Klinklang.
Pokémon with Steel as one of their types: 65